SMAD4 and hepatocellular carcinoma: Lan et al. (2014) determined that autophagy selectively regulates the expression of the oncogenic miR-224 through autophagosome-mediated degradation. In vitro miR-224 plays its oncogenic role in hepatoma cell migration and tumor formation through silencing its target gene Smad4. The authors showed that autophagy is downregulated and inversely correlated with miR-224 expression in HBV-associated HCC patient specimens, and they demonstrated a significant correlation between low expression of ATG5, high miR-224, and low Smad4, with overall poor survival rate in HBV patients (Lan et al., 2014).